[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Perceived DU Ratio (PDUR) is a measure with which the quality of TV pictures imsaired by ghosts is objectively determined. It is defined as the power sum of levels for individual ghost (D/U), weighted by subjective effects due to r. f. phase (∅) and delay time (τ).
It was difficult to make outdoor measurement of PDUR directly because the aid of a large computer was inevitable. The newly developed PDUR measuring equipment is portable, introducing digital technique involving micro-processor, which makes it possible to measure PDUR within 60 seconds for each TV channel. Not only PDUR but also D/U, ∅ and τ can be measured simultaneously. The measured PDUR accuracy is within ±2dB at less than 30 dB PDUR. This accuracy is sufficient for practical use.
Field tests were made using the PDUR measuring equipment in an area suffering from ghost interference. It was shown that measured PDUR considerably varies with a slight movement of the position of the receiving antenna because of the existance of standing waves due to waves reflected by objects around the receiving site.

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